Northwest Inland

Poor - Timing, track, or intensity of incoming weather is uncertain

A series of frontal systems will continue to affect the region over the next few days. In general, expect 5-15cm of snow each 12 hour period, with strong W-SW winds. Tuesday: 10-15cm of snow. Winds backing off to Mod-Strong from the SW. Freezing level (FL) around 600m. Wednesday: 15-20cm. Strong SW winds. FL rising to 1200m. Thursday: 5-10cm. Strong SW winds. FL around 1000m.

There is one new report of a Size 1.5 natural slab avalanche from the NW part of the region. It occurred on Saturday and may have released on the mid-December surface hoar at around 1100m on a north aspect.

Strong winds have been the biggest storey recently. Exposed windward slopes have been scoured and wind slabs have formed in lee terrain and may be susceptible to human triggering. There is now around 55-70cms of snow sitting on a surface hoar/crust/facet combo which is the result of the early December dry spell. This crust is widespread and exists in most start zones up to 2000m. Facets can reportedly be found above or below the crust. Prior to being buried, the surface hoar was destroyed by high winds in the alpine, but still coexists with the crust at treeline and below. What is the tipping point of this weak interface? In areas where this interface has reached its threshold, natural and human triggered avalanches up to size 2.5 have occurred. If they have yet to happen, I suspect they are gaining some strength but would still react to a rider trigger, especially in steeper, unsupported terrain features. In short, the upper snowpack is variable and deserves caution. It will also see increased load with forecast wind and snow. Beneath this the midpack is well settled and strong.